While an asteroid is far too small to cover the sun, one will occasionally move directly in front of one of the many stars in the night sky and block its light from view, causing a stellar occultation.

Since asteroids move relatively fast, these events typically last just a few seconds. Normally the occulted star is so faint the event can only be seen via telescope.

During Thursday-Friday night, however, a star visible to the naked eye, Delta Ophiuchi (the fourth brightest star in the constellation Ophiuchi), will be occulted by asteroid Roma, which is about 50 km across, according to a statement of the European Space Agency.

This means the occultation will be visible only along a path about 50 km wide, crossing central Europe, Spain and the Canary Islands.